There have been reported some methods for production of (2R)-2-fluoro-2-C-methyl-D-ribono-γ-lactone precursors. In any of these production methods, the stereoselective introduction of a fluorine atom to 2-position is a significant problem. Ring-opening fluorination of a cyclic sulfuric ester is known as a fluorine atom introduction technique suitable for mass-scale production (see Patent Documents 1 and 2 and Non-Patent Document 1). Using this technique, it is feasible to produce a (2R)-2-fluoro-2-C-methyl-D-ribono-γ-lactone precursor in the form of a ring-opened fluorinated compound in three steps (first step: cyclic sulfurous esterification, second step: oxidation, third step: ring-opening fluorination) from a 1,2-diol substrate (see Scheme 1 where Me is a methyl group; Et is an ethyl group; X+ is a proton, a protonated organic base, a metal cation, a tetraalkylammonium or a tris(dialkylamino)sulfonium; and Bz is a benzoyl group). There is also reported a modified production method for producing a ring-opened fluorinated compound in two steps (first step: cyclic sulfuric esterification, second step: ring-opening fluorination) from a 1,2-diol substrate by directly converting the 1,2-diol to a cyclic sulfuric ester with the use of sulfuryl chloride or 1,1′-sulfonyl diimidazole. However, the aforementioned three-step production method is suitably adopted rather than the modified two-step production method in order to obtain the ring-opened fluorinated compound with high yield and high reproductivity.

On the other hand, the present applicant has disclosed dehydroxyfluorination of an alcohol in the presence of sulfuryl fluoride (SO2F2) and an organic base (and optionally, a “salt or complex of an organic base and hydrogen fluoride”) (see Patent Document 3).